21012022110221 has 4 divisors (see below), whose sum is σ = 21012185976672. Its totient is φ = 21011858243772.

The previous prime is 21012022110137. The next prime is 21012022110223. The reversal of 21012022110221 is 12201122021012.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21012022110221 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21012022110221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21012022110223) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 81740735 + ... + 81997388.

It is an arithmetic number, because the mean of its divisors is an integer number (5253046494168).

Almost surely, 2^{21012022110221} is an apocalyptic number.

It is an amenable number.

21012022110221 is a deficient number, since it is larger than the sum of its proper divisors (163866451).

21012022110221 is a wasteful number, since it uses less digits than its factorization.

21012022110221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 163866450.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 21012022110221 its reverse (12201122021012), we get a palindrome (33213144131233).

The spelling of 21012022110221 in words is "twenty-one trillion, twelve billion, twenty-two million, one hundred ten thousand, two hundred twenty-one".